Definition: PIN stands for personal identification number. "PIN number" is redundant because you don't need to say "number" twice. You use your PIN number to verify your identity. It is a secret number that you use to access your bank accounts.
For example, when you take money out of an ATM, you enter your PIN number to prove that you're authorized to make the withdrawal. You might also enter a PIN number if you use your debit card at a retailer (only for POS transactions, not signature transactions).
you should keep this number secret, protect it, and never write it on your card.
